Plant growth regulators

ABSTRACT

A method of regulating and/or modifying the growth of plants by applying to the plant locus, certain beta-substituted ethanesulfinic acids, and oxygen esters thereof, is described as well as plant growth regulant formulations containing them. Some of the compounds described for use in the method of the invention are novel.

' United States Patent Pilgram et al.

[451 Dec. 16, 1975 PLANT GROWTH REGULATORS Inventors: Kurt H. G. Pilgram; Earl K.

Jackson; Willy D. Kollmeyer, all of Modesto, Calif.

Assignee: Shell Oil Company, Houston, Tex.

Filed: Dec. 10, 1974 Appl. No.: 531,257

Related US. Application Data Division of Ser. No. 253,356, May 15, 1972, Pat. No. 3,876,678, which is a continuation-in-part of Ser. No. 162,709, July 14, 1971, abandoned.

u.s. c1 260/456 NS 1m. cl. c07c 145/00 Field of Search 260/456 NS; 71/103 References Cited UNITED STATES PATENTS 3/1962 Carlson 260/456 NS Aichenegg 260/456 NS Hofer et al 71/103 Primary Examiner-James 0. Thomas, Jr. Assistant Examine'rNicky Chan 5 7] ABSTRACT 5 Claims, No Drawings PLANT GROWTH REGULATORS This'is a division of application Ser. No. 253,356, filed May l5, 1972, now Pat. No. 3,876,678, which in turn is "a contil luation-in-part of Ser. No. 162,709, filed July 14, 1971, now abandoned.

, BACKGROUND OF Tl-IE INVENTION 1. Field of the Invention This invention relates to the discovery thatv betachloro-and beta-bromoethanesulflnic acidsand esters can "be employed to regulate and/or modify thegrowth of plants.

2. Description of the Prior Art Certain of the lower alkyl ethanesulfinate esters which are active in the method of the inventiofi are known compounds. German Pat. No. 2,005,514 discloses the methyl, ethyl and isopropyl esters of 2- chloroor bromoethanesulfinic acid as anti-cancer agents. The preparation of the tertiary butyl ester of 2-chloroethanesulfinic acid is disclosed in V. S. Etlis et 21., Journal General Chemistry USSR. 35, 472-75 (1965 Also,-one of the free sulfinic acids useful in the method of the invention, 2-chloroethanesulfinic acid, is disclosed in A. I. Titov and A. N. baryshnikova, Dokl. Akad. Nauk., SSR, 157, 681 (1964) and H. Distler, Angew. Chem. Inlernata Ed. 4, 300 (1965). However, no reference is known which discloses or suggests the plant growth regulant properties of these known compounds or the class of compoundsas a whole which have been found to be active in the process of the invention. Other related art is O. Hesse et al., Chem. Ber. 90, 2106 (1957) which discloses the barium salt of 2-hydroxyethanesulfinic acid and U.S. Pat. No. 2,412,909 which discloses a general reaction wherein unspecified alkyl or substituted alkyl sulfinyl halides may be reacted with alcohols, phenols, etc. to form products which are useful as bleaching agents, dyes, plasticizers and a variety of other uses, but not including plant growth regulators.

' SUMMARY OF THE INVENTION Surprisingly, it has now been discovered that certain ethanesulfinic acids and oxygen esters thereof wherein the beta carbon atom of the ethylene moiety is substituted with bromine or chlorine, can be employed to regulate and/or modify the growth of plants. Depending on variables such as the species of plant treated, plant maturity at time of treatment, the quantity and concentration of growth-regulant used, the specific compound used, and the formulation employed, these compounds when applied to the plant locus exhibit a wide variety of useful plant growth regulating properties. Some of the plantgrowth regulant effects which have been observed include the promotion of early and v more uniform fruit ripening and/or abscission, acceleration of leaf abscission, promotion of flowering, stimulation of sprouting of tubers, stimulation of seed germination, destruction of apical dominance in tubers causinglateral buds to sprout, increased formation of root initials on tomato stems, the causation of tomato leaf ep nasty and dwarfing of plants. It will be recognized that biological response such as that realized from the process of the instant invention, when utilized as a cultural practice in the agricultural industry, can provide a valuable means of increasing crop productivity while-at the same time reducing the labor and expense necessary to produce the crops.

2 -The invention accordingly, is the use of beta-substituted ethanesulfinic acids and esters, hereinbefore described as plant growth regulators and plant growth regulant formulations containing them.

2-Bromoethanesulfinic acid and many of the sulfinic esters useful in the process of the invention are novel. Therefore, the scope of the present invention also encompasses these novel compounds.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The beta-substituted ethanesulfinic acids and esters found useful to regulate the growth of plants according to the method of this invention are represented by formula I:

wherein X represents bromine, chlorine or alkoxy of up to 3 carbon atoms; R is hydrogen, alkyl of up to 20 carbon atoms, aryl of up to 10 carbon atoms, alkenyl or up to 8 carbon atoms, alkynyl of up to 4 carbon atoms or ZR wherein Z is alkylene of up to 4 carbon atoms and R is alkylthio of up to 3 carbon atoms or alkoxy of up to 4 carbon atoms, or hydroxy; if X is chlorine, R also represents ZR wherein Z is as defined above and R is a beta-chloroethanesulfinyloxy moiety. Any of these alkyl these alkyl groups may be of either straight chain or branched chain configuration.

Exemplary species of the class of the invention include:

Z-methoxyethyl 2-chloroethanesulfinate propyl 2-bromoethanesulfinate 2-bromoethanesulfinic acid phenyl 2-bromoethanesulfinate naphthyl 2-chloroethanesulfinate 2-(ethylthio)ethyl 2-bromoethanesulfinate 2-methoxypropyl 2-bromoethanesulfinate 2-butoxypropyl 2-chloroethanesulfinate propynyl 2-bromoethanesulfinate Many of the compounds active in the method of the invention have not previously been known in the art. Thus, the following are considered to be novel compounds and form a preferred aspect of this invention (symbols refer to formula 1, above):

I. Sulfinic Acids The compound wherein X is bromine and R is hydrogen.

Il. Sulfinate Esters Compounds wherein X is chlorine or bromine, R is alkyl of from 6 to 20 carbon atoms, alkynyl of up to 4 carbon atoms, alkenyl of up to 8 carbon atoms, aryl of up to 10 carbon atoms, or ZR wherein Z is alkylene of up to 4 carbon atoms and R is alkylthio of up to 3 carbon atoms or alkoxy of up to 4 carbon atoms or hydroxy; and if X is chlorine, R also represents ZR wherein Z is as defined above and R represents a betachloroethane-sulfinyloxy moiety.

Of the generic class of compounds useful in the method of this invention, certain species in the sulfinic ester subclass are especially effective in regulating the growth of plants, thus compounds wherein X is chlorine, and R is alkyl of up to 20 carbon atoms or alkenyl of up to 8 carbon atoms make up another preferred aspect of this invention.

Specific examples of this preferred subclass include:

methyl 2-chloroethanesulfinate amyl 2-chloroethanesulfinate 3-butenyl 2-chloroethanesulfinate heptyl 2-chloroethanesulfinate decyl 2-chloroethanesulfinate 3-pentenyl 2-chloroethanesulfinate The compounds of this invention may be applied to seeds prior to planting or to soil surrounding the plants, or to plants, pre-emergence, or at harvest to modify and/or regulate the growth of the plant, or optionally may be applied to stimulate, regulate and/or modify ripening of the harvested portion. For application. compounds of the invention, being either solid or liquid at ambient temperatures, may be formulated using conventional techniques and employing adjuvants and- /or modifiers which are known in the agricultural chemical art to provide compositions in the form of wettable powders, dusts, granules, pellets, solutions, emulsifiable concentrates, emulsions and pastes.

Preferred for use on maturing plants or harvested crops are those formulations which furnish the active ingredient to the plant locus in liquid or paste form. These preferred formulations would include wet-table powders, solutions, emulsifiable concentrates, emulsions and pastes. Wettable powders are water-dispersible compositions containing the active ingredient in proportions ranging from 10 to 90% of the total composition, and an inert solid carrier such as one of the natural clays or a synthetic mineral filler derived from silica and silicate. Optionally, such wettable powder may also contain 3-10% of a dispersing agent and where necessary Ol% of stabilizer(s) and/or other additives such as penetrants or stickers. The term solution includes both aqueous and non-aqueous solutions of the compounds of the invention. Certain of the compounds of the invention are soluble in aqueous media and can be formulated and applied in aqueous solution at concentrations up to Other compounds of the invention are less or sparingly soluble in water and exhibit proportionally higher solubility in non-aqueous solution and may be formulated and applied at concentrations of up to 50%. The emulsifiable concentrates contemplated for use in the method of the invention usually contain, in addition to the solvent and, when necessary, co-solvent, l050% w/v active ingredient, 2-20% w/v emulsifiers and 020% appropriate additives such as stabilizers, penetrants and corrosion inhibitors. Pastes are compounded so as to obtain a stable flowable product and usually contain 10-60% active ingredient, 2-20% of appropriate additives, and, as carrier, water or an organic liquid in which the plant growth regulator is substantially insoluble.

For season long treatment, i.e., application at time of planting or application to plants in early stages of growth, or for other specialized applications, solid formulations of the compounds of the invention may be desired. Suitable solid formulations would include dusts, granules and pellets. Dusts usually have a composition similar to that of a wettable powder but without a dispersant, and normally contain /2 to 10% of plant growth regulator. Dust may also be formulated as concentrates which are then usually diluted further with solid carrier in suitable blending equipment prior to use in the field. Granules and pellets are usually prepared to have a size between 10 and 100 B5 mesh, and may be manufactured by agglomeration compaction or impregnation techniques. Generally, granules will contain /a-25% of plant growth regulator plus additives such as stabilizers, slow-release modifiers, binding agents, etc. Except where indicated otherwise, all percentages given in this and the preceeding paragraph are percentages by weight.

To achieve the plant growth regulating and modifying effects hereinbefore described, formulations of the compounds of the invention may be applied directly to the plant fruit or as foliar-soil treatments, seed treatments, foliar treatments or soil treatments. The rate of application will be dependent on thetype of application technique utilized as well as other factors such as the particular active agent used, the particular formulation employed, the particular species of plants involved, the maturity stage of the plant, the types of effect desired and the local conditions; for example, temperature, humidity, soil moisture, chemical makeup of the soil and the like. In general, for plants In agronomic environment, rates from 0.05 to 20 pounds per acre can be used to stimulate and/or modify plant growth. However, the preferred rates for most uses range between 0.] and 5.0 pounds per acre. For application to the plant fruit or harvested crop, the rate of application may range between 1 and 20,000 ppm (parts per million based on total fruit weight) with rates of from to 4,000 ppm being preferred.

The compounds of this invention as described by formula I, above, may be prepared by the following synthesis techniques.

I. Sulfinic Acids (compounds wherein R is hydrogen) The beta-substituted ethanesulfinic acids of this invention may be prepared by the reaction of a beta-substituted ethanesulfinyl chloride of the formula ll wherein X is bromine or chlorine, with water This reaction is suitably carried out in an inert organic solvent such as ether and the by-product hydrogen chloride, which is generated in the reaction, is effect vely removed by sparging the reaction mixture with nitrogen during the reaction period.

The beta-substituted ethanesulfinyl chloride described by formula II can be prepared by oxrdatrve chlorination of the corresponding bis( beta-substitutedethyl) disulfide wherein the beta substituents of the disulfide are the same as the beta substrtuent on the sulfinyl chloride. This technique, which utilizes a general method described by l. B. Douglass and R. V. Norton, Journal of Organic Chemistry, 33, 2104 (1068) for conversion of certain disulfides to sulfinyl chlorides, involves the reaction of chlorine gas with the b s(betasubstituted-ethyl) disulfide in glacial acetic acid The bis(beta-substituted-ethyl) disulfide reactants utilized in the synthesis technique described above are known in the art, e.g. see G. Y. Epshtein et al., J. Gen. Chem. USSR, 34, 1961 (1964); see also, Fuson et al., J. Org. Chem. II, 491 (1946).

II. Sulfinate Esters All of the beta-substituted ethanesulfinate esters described by formula I above, except compounds wherein R is aryl, may be prepared by the reaction of a betasubstituted ethanesulfinyl chloride of the formula ll with a hydroxy compound of fonnula III as illustrated by equation I, below Equation 1 wherein X is as defined in formula I above and R represents all the moieties defined for R in formula I above except aryl. This reaction is suitably carried out in an inert solvent such as ether and at reaction temperatures less than ambient. Due to the highly reactive nature of the sulfinyl chloride, the reaction is preferably carried out under an inert (nitrogen) atmosphere.

Beta-substituted ethanesulfinate esters of this invention wherein R is aryl may be prepared by the reaction of a thallium(l) salt of a hydroxy compound of formula V1 with a beta-substituted ethanesulfinyl chloride of formula II as illustrated by equation 11 below. This reaction is suitably performed in an inert solvent such as ether or benzene under an inert atmosphere.

The products of this reaction are most suitably purified by molecular distillation.

The following examples are illustrative of methods of preparing the compounds of this invention and their use in regulating plant growth. In these examples, parts by weight (w) and parts by volume (v) bear the same relation as the kilogram to the liter and all temperatures are in degrees Centigrade. In all cases, the structures of the compounds prepared were confirmed by infrared spectra, nuclear magnetic resonance spectra and elemental analyses.

EXAMPLE I 2-Chloroethanesulfinic Acid Bis( 2-chloroethyl) disulfide was oxidatively chlorinated according to the general method disclosed in I. B. Douglass and R. V. Norton, Journal of Organic Chemistry, 33, 2104 (1968) as follows: Bis( 2,-chloroethyl) disulfide (38.0 w) was charged into a reaction vessel containing glacial acetic acid (24.0 w) and the mixture was cooled to Chlorine gas was introduced to the cooled solution at a rate such that the reaction mixture was maintained at about 10. The chlorine addition was continued until the deep orange color of the reaction mixture disappeared. The solution was then distilled at reduced pressure to yield a clear liquid, 2-chloroethanesulfinyl chloride (50.4 w), boiling point 8282 under reduced pressure (12 torr).

Water (3.6 w) was added in one portion to a solution of 2-chloroethanesulfinyl chloride (29.4 w) in ether (250 v). The reaction mixture was held for one hour at ambient temperatures during which time a vigorous stream of nitrogen was bubbled through the mixture. Upon completion of the hold period, the reaction solution was concentrated by distillation in a vacuum to give a colorless liquid (26.4 w). Further purification of this liquid by molecular distillation at 75 and 1 X 10 torr provided a colorless viscous oil, 2-chloroethanesulfinic acid (14.5 w).

EXAMPLE II II 2-(Ethyl)hexy1 2-chloroethanesulfinate A stirred portion of 2-chloroethanesulfinyl chloride (16.2 w) prepared as in Example I, cooled to l5 to 30C, was treated dropwise with 2-ethylhexanol 13.0 w) under a nitrogen atmosphere. Upon completion of the addition the external cooling was removed and the reaction mixture was allowed to stand for 16 hours at ambient temperature. Distillation through a 20 cm Vigreux column afforded a clear white liquid, (2- ethyl)hexyl 2-chloroethanesulfinate (14.7 w) boiling at 1 10 to 1 12 under reduced pressure (0.3 torr).

EXAMPLE lIl Butyl 2-chloroethanesulfinate 2-Chloroethanesulfinyl chloride (16.2 w), prepared as in Example I was dissolved in dry ether v) and the solution was cooled to 3115". Normal butanol was added dropwise under a nitrogen atmosphere to the cooled solution. Upon completion of the addition period the reaction mixture was allowed to warm to ambient temperatures and the solvent was removed by distillation in a vacuum to yield a colorless liquid, butyl 2-chloroethanesulfinate (18.5 w).

EXAMPLE IV 2-( Chloroethanesulfinyloxy )ethyl 2-chloroethanesulfinate Ethylene glycol (6.2) was added dropwise under a nitrogen atmosphere to a stirred solution of 2-chloroethanesulfinyl chloride (14.7 w), prepared as in Example l, in dry ether (40 v). During the addition period the temperature of the reaction was controlled at 20 by external cooling. Upon completion of the addition, the reaction mixture was warmed to ambient temperature and the solvent was removed by distillation in a vacuum. Examination of the residue by gas-liquid chromatography revealed more than one major component. The residue was then redissolved in dry ether (200 v) and further treated with 2-chloroethanesulfinyl chloride (14.7 w) as above. Using the same procedure as above an oily residue was obtained which after purification in a wiped film molecular still yielded a colorless liquid, 2-(chloroethanesulfinyloxy)ethyl 2-chloroe- 7 thanesulfinate (8.5 w) boiling at 110-1I5 under reduced pressure (1 X 10 torr).

EXAMPLE V 2-(Ethylthio)ethyl 2-chloroethanesu1finate EXAMPLE VI Phenyl 2-chloroethanesulfinate cl -CH CH -S-O A suspension of thallium(l) phenoxide (28.6 w) in dry ether (100 v) was rapidly treated with 2-chloroethanesulfinyl chloride, prepared as in Example I. The slurry was vigorously stirred for 1 hour at ambient temperature with exclusion of moisture. Removal of thallium(I) chloride by filtration and evaporation of the ethereal filtrate solution gave an oil. The oil was then subjected to molecular distillation in a wiped-film apparatus at 7075 (1 X 10 torr) to give phenyl 2- chloroethanesulfinate (122 w) as a mobile liquid.

EXAMPLE VII Following procedures similar to those given in previous examples, the following other species of the compounds of the invention were prepared (symbols refer to formula I).

Table I or Boiling Point. C (torr) EXAMPLE VIII Fruit Abscission Washington Navel oranges were harvested in a manner such that the fruit was still attached to 4 inches of stem having two (2) clusters of leaves. The pull force required to cause abscission of the fruit from the cut stems was 14-16 pounds. The harvested oranges were then segregated into groups of five (5) oranges each (stems and leaves still attached) and the segregated groups were sprayed to dripping with several concentrations of methyl 2-chloroethanesulfinate in aqueous solution. A water treatment was used as a control. Some oranges began to drop off the stems 2 days after treatment with the higher concentrations of methyl 2-chloroethanesulfinate while the fruit in the control groups remained attached to the stems. The rates of application as well as the observations of the fruit abscission occurring 7 days after treatment for both the treatment groups and the control group are recorded in Table II below.

Table II Concen- Number of tration Oranges Separated Treatment (ppm) From Stems Water 2 methyl 2-chloroethanesulfinate 4000 5 methyl 2-chloroethanesulfinate 2000 5 methyl 2-chloroethanesulfinate 1000 3 EXAMPLE IX Fruit Ripening EXAMPLE X Stimulation of Seed Germination Under normal conditions experience has shown that only 40% of cocklebur seeds will germinate. Fifty cocklebur seeds were soaked for 1 hour in either water or methyl 2-chloroethanesulfinate at 1000 ppm w/v water. All seeds were planted and allowed to germinate over a 10 day period. Treatment with methyl 2-chloroethanesulfinate increased seed germination by 25% over the controls.

EXAMPLE XI Stimulation of Tuber Sprouting Twenty-four yellow nutsedge tubers were soaked in a ppm aqueous solution of methyl 2-ch1oroethanesulfinate for 10 minutes, blotted dry and sealed in a bottle. A like number of tubers were soaked in water and sealed according to the same procedure. Six days after treatment all (100%) of the treated tubers had sprouted whereas only 81% of the control tubers had 9 sprouted. Also, the number of shoots formed per tuber increased from 1.3 for the control group to 1.6 for the treatment group. Treatment with methyl 2-chloroethanesulfinate, therefore, stimulated sprouting and 10 green harvested tomatoes. in this experiment green mature tomatoes were picked from plants grown in a greenhouse and randomly segregated into groups of ten each for treatment. The treatment chemicals were destroyed the normal dominance of the apical bud thus made up in water/acetone solutions at a concentration allowing lateral buds to sprout. of 1000 ppm and each group of tomatoes was soaked for 1 hour in one of the solutions containing a treat- EXAMPLE XII ment chemical or in the base solution without chemi- Leaf Abscission cal. Each tomato in each group was evaluated daily by lnd1v1dual branches of Washmgton Navel orange g gy ififl 225 2 2 221 2:? trees were treated with aqueous solutions of several of 2 g 55 S t t g p a the compounds of the invention. Each of the com- {i np.e( S 8 233 T fi g g g pounds tested was made up as a 2000 ppm solution in 2 1?; e H t d in Tfble Iv belowq g water containing 0.2% Tronic as surfactant. A total of e S are S e Table IV Percent Ripeness Days After Treatment Treatment l 2 3 4 5 6 7 8 9 l0 14 Control 3 3 8 I8 28 38 63 68 so 93 98 2-chloroethanesulfinic acid 13 48 55 68 75 78 85 9o 95 ethyl 2-chloroethanesulfinate 10 1o 30 38 53 58 73 83 83 93 2-propynyl 2-chloroethanesulfinate a 25 45 60 68 78 8o 83 9o 98 isopropyl 2-chloroethanesulfinate 8 10 28 3s 53 60 68 73 75 95 allyl 2-chloroethanesulfinate 8 11 22 28 42 58 67 72 86 95 octyl 2-chloroethanesulfinate 8 8 15 25 35 48 55 58 65 83 I 98 2-butoxyethyl 2-chloroethanesulfinate 6 11 19 36 56 64 75 78 8o 92 100 2-(chloroethanesulfinyloxy)- ethyl 2-chloroethanesulfinate 5 10 25 43 48 65 75 75 8o 85 100 butyl 2-chloroethanesulfinate 5 15 23 40 58 70 78 78 8o 83 hexyl 2-chloroethanesulfinate 5 s 33 43 55 63 78 85 93 93 Z-ethyl hexyl Z-chloroethanesulfinate 5 5 i8 23 33 55 68 70 78 88 98 2-(ethylthio)ethyl 2-chloroethanesulfinate 5 5 l0 i8 35 43 58 63 65 70 90 methyl Z-chloroethanesulfinate 3 5 1o 18 33 38 48 50 63 70 88 eicosyl 2-chloroethanesulfinate 3 8 2o 30 33 50 58 70 80 85 93 As indicated in the table above, the compounds of 100 m] f each f thepresulting solutions was applied as the lnvention m this test were most effective 1n stlmua foliar spray to a single branch of Washington Navel P early "P P W test plants- Thls effect orange trees Seven days after treatment some f the 45 illustrated by the relat1ve ripeness values at 5 days after leaves on the treated branches became stiff, although treatmentstill green, and began to fall from the trees. Observa- EXAMPLE XIV tions of the defoliation caused by each chemical six I weeks after treatment are recorded in the following Fruit Rlpenmg table. Evaluation of defoliation was based on four clas- 50 This test was conducted to evaluate the efficacy of Slficatlonsl F 1 1 to t0 60% and 61 t0 the compounds of the invention as ripening agents for 100% absclsslon of the leaves orlgmally Present mature fruit prior to harvest, i.e., fruit still attached to the growin lant. Individual clusters of mature reen Table III P 8 C dT t cherry tomatoes grown 1n a greenhouse were treated f 7 55 with the compounds of the invention while still on the 11: 1: 1 2i1tihlorogthaneriglfirlate 1 :0 18 vine. For treatment, the test compounds were made up e y -C OI'OE anesu ma e O gimpmpyl 2 chlrethanesumnam to 10 1n a acetone/water solution at a concentrauon of 1000 hexyl 2-chloroethanesulfinate 1 1 to 30 ppm and each test solut1on was applied thoroughly to a W1zfchlmwhanesulfinaie different set of 4 clusters of tomatoes, each cluster 60 having 4 to 6 mature tomatoes. One set of tomatoes was treated with the base solution for control purposes. None of the leaves dropped from the untreated control The results are listed in Table v below branches or those sprayed with the base solution.

. Table V EXAMPLE 65 Red Tomatoes Fruit Ripening A second experiment was conducted to evaluate the efficacy of the compounds of the invention in ripening Days After Treatment Table V-continued 7: Red Tomatoes Days After Treatment EXAMPLE XV Fruit Ripening Picked, green, untreated bananas were separated and randomly grouped for treatment. The treatment con sisted of spraying each of the different treatment groups, one untreated group being retained as a control, with a 1000 ppm aqueous solution of one of the following compounds of the invention: methyl 2- chloroethanesulfmate and hexyl 2-chloroethanesulfinate. In all cases the treated bananas turned completely yellow 2 to 5 days before the untreated bananas.

EXAMPLE XVI Leaf Epinasty Table Vl-continued Compound'Tested Degree of Leaf Epinasty cetyl 2-chloroethanesulfinate 3O methyl Z-chloroethanesulflnate 30 lauryl 2-chloroethanesulflnate complete allyl Z-chloroethanesulfinate 30 methyl Z-bromoethanesulfinate 60 EXAMPLE XVlll Leaf Epinasty A second leaf epinasty test was performed on tomato plants. In this test phenyl Z-chloroethanesulfinate as the test compound was applied as a foliar spray to 3 different tomato plants. Two plants were 37 days old. The older plants were 14 inches high with 10 leaves and the younger third plant was 23 days old. The older plants were 14 inches high with 10 leaves and the younger plants were 10 inches high with 8 leaves. Two ages of plants were included because the older plants usually are more sensitive and give a more rapid hormonal epinasty response. The test compound was dissolved in acetone and diluted to 2500 ppm with water containing 0.4% surfactant (Wilsco Foamspray). A 10 ml volume of the test compound so diluted was applied as a foliar spray to 3 tomato plants. The treated plants were evaluated for epinasty (bending of leaves downward toward the base of the stem) 20 hours after treatment. The test was again evaluated for epinasty as well as phytotoxicity four days after treatment, to determine if the epinasty effects had dissipated. The results of the test including those obtained for the control (base solution without test compound) are recorded in Table IX below. The table heading leaves normal after 4 days designates visual observation of whether any effects of epinasty remained 4 days after treatment.

Table IX Percent of Leaves Showing Epinasty Response Leaves lnter- Normal No Slight mediate Complete After Phyto- Treatment Response Response Response Response 4 Days Toxicity Control 100 0 0 0 Yes None Phenyl Z-chloroethanesulfinate 0 59 8 33 Yes None out the test for epinasty response; the observations of leaf epinasty which had occurred 13 days after treatment are recorded in Table VI below. Evaluation of the degree of leaf epinasty is based on four classifications: no epinasty indicating normal horizontal leaf growth, complete epinasty (90) indicating that the leaves grew vertically downward around the steam and 30 or 60 epinasty indicating intermediate downward growth of leaves.

Table VI Compound Tested Degree of Leaf Epinasty Control None ethyl Z-chloroethanesulflnate 30 isopropyl 2-chloroethanesulfinate 6O hexyl Z-chloroethanesulfinate complete octyl 2-chloroethanesulfmate We claim as our invention: 1. A compound of the formula ZR in which Z is methylene and R is methoxy. 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 wherein X is chlorine.
 3. A compound according to claim 2 wherein R is ZR'' in which Z is ethylene and R'' is hydroxy.
 4. A compound according to claim 2 wherein R is ZR'' in which Z is ethylene and R'' is butoxy.
 5. A compound according to claim 2 wherein R is ZR'' in which Z is methylene and R'' is methoxy. 